System and method for machine tool maintenance and repair

ABSTRACT

A system and a method for machine tool maintenance and repair is provided for allowing an expert at a remote site to collaborate with an on-site personnel to maintain or repair a physical machine in a manner of combining the physical machine with a virtual reality (VR) model or an augmented reality (AR) model. Two maintenance modes are provided, which are an augmented virtual reality model guided by a standard operation procedure (referred as a SOP-AVR mode), and an augmented virtual reality model guided by an expert operation procedure (referred as an EG-AVR mode). A cyber physical agent (CPA) is adopted for simultaneously monitoring and repairing plural machines of the same machine type.

RELATED APPLICATIONS

This application claims the benefit of the Provisional Application Ser. No. 62/475,889, filed on Mar. 24, 2017. The entire disclosures of all the above applications are hereby incorporated by reference herein.

BACKGROUND Field of Invention

The disclosure relates to a system and a method for machine tool maintenance and repair, and more particularly, to a system and a method for machine tool maintenance and repair by using a virtual reality (VR) or augmented reality (AR) technology.

Description of Related Art

In an after-sale service, maintenance and repair is an important task provided to a client after a machine tool is delivered, and machine malfunctions often interrupt the production at the client side, thus resulting in cost loss.

In general, a conventional tool maintenance method still relies on an electronic or paper manual for inspecting a machine tool, and sometimes a maintenance instruction film may be recorded and provided for teaching and enabling a maintenance personnel to perform tool maintenance and repair by using audio-video instructions besides literal instructions. For example, when a spindle of a machine tool is out of order, maintenance personnel may first look for the maintenance data of the spindle for inspecting the spindle, and thus the maintenance personnel has to look up in the manuals to find out the solutions according to the actual failure causes of the spindle. However, this convention tool maintenance and repair method merely has literal descriptions with few corresponding photos, and thus it takes a lot of time for a maintenance notice to recover the spindle. When being shown in a video mode (maintenance film), the maintenance data may be shown by using images, sound and words. However, the maintenance film shows all the problems linking to the solutions, such that the maintenance personnel will have difficulty in finding main points for processing, thus prolonging the maintenance time.

On the other hand, a processing plant generally has several machine tools using the same cutting tool product (type). It takes a lot of time to judge the abnormal statuses of the machine tools one by one, and it is quite likely to make wrong judgements. Hence, there is need to develop and provide a method for simultaneously monitoring and maintaining several machine tools.

SUMMARY

An object of the disclosure is to provide a system and a method for machine tool maintenance and repair, thereby shortening the maintenance time by using a virtual reality (VR) manner or an augmented reality (AR) manner.

Another object of the disclosure is to provide a system and a method for machine tool maintenance and repair, thereby using a cyber physical agent (CPA) to simultaneously monitor and repair plural machines of the same machine type.

According to the aforementioned objects, an aspect of the disclosure is to provide a system for machine tool maintenance and repair, the system includes at least one machine tool, a human cyber physical system, a cyber-physical agent (CPA) and an on-site device. Plural sensors are installed on each of the at least one machine tool for collecting plural sets of state data of the machine tool that is in operation, and the at least one machine tool has the same tool type. The human cyber physical system has a visual initial-state model and a standard maintenance procedure, in which plural component models of respective parts of the machine tool are built in accordance with measured dimension data of the parts of the machine tool, and the component models are assembled to form the visual initial-state model in accordance with exploded view data of the machine tool. The human cyber physical system analyzes periodical maintenance conditions and abnormal states encountered by the machine tool that is in operation, thereby building the standard maintenance procedure. The CPA is communicatively connected to the at least one machine tool and the human cyber physical system for receiving the standard maintenance procedure and the sets of state data, in which the CPA or the human cyber physical system updates the visual initial-state model as a visual operating-state model in accordance with the sets of state data, and the CPA obtains an event standard maintenance procedure from the standard maintenance procedure in accordance with the sets of state data. The on-site device is communicatively connected to the CPA for enabling an on-site personnel to access the visual operating-state model and the event standard maintenance procedure.

In some embodiments, the aforementioned system further includes an expert device communicatively connected to the human cyber physical system for enabling an expert to access the visual operating-state model, in which the expert device provides an expert maintenance procedure to the on-site personnel.

In some embodiments, the visual initial-state model and the visual operating-state model are VR models or AR models, and the on-site device and the expert device are VR devices or AR devices.

In some embodiments, the at least one machine tool is a rotary machine, and the sensors includes a dynamometer, an energy consumption sensor and a temperature sensor.

In some embodiments, the aforementioned system further includes a cloud layer, a networking layer and a factory layer. The cloud layer includes the human cyber physical system, the factory layer includes the at least one machine tool and the CPA, and the networking layer communicatively connects the factory layer to the cloud layer.

According to the aforementioned objects, another aspect of the disclosure is to provide a method for machine tool maintenance and repair. the method includes installing plural sensors on each of at least one machine tool for collecting a plurality of sets of state data of the machine tool that is in operation; building plural component models of respective parts of the machine tool in accordance with measured dimension data of the parts of the machine tool, and assembling the component models are assembled to form a visual initial-state model in accordance with exploded view data of the machine tool; analyzing periodical maintenance conditions and abnormal states encountered by the machine tool that is in operation, thereby building a standard maintenance procedure; storing the visual initial-state model and the standard maintenance procedure in a human cyber physical system; communicatively connecting a cyber-physical agent (CPA) to the at least one machine tool and the human cyber physical system for receiving the standard maintenance procedure and the sets of state data; updating the visual initial-state model as a visual operating-state model in accordance with the sets of state data, and obtaining an event standard maintenance procedure from the standard maintenance procedure in accordance with the sets of state data; and communicatively connecting an on-site device to the CPA for enabling an on-site personnel to access the visual operating-state model and the event standard maintenance procedure.

In some embodiments, in the aforementioned method, an expert device is communicatively connected to the human cyber physical system for enabling an expert to access the visual operating-state model, and the expert enters an expert maintenance procedure into the expert device, and the expert device uploads the expert maintenance procedure to the human cyber physical system, thereby enabling the on-site personnel to access the expert maintenance procedure through the on-site device.

In some embodiments, the aforementioned method further includes disposing the human cyber physical system in a cloud layer; disposing the at least one machine tool and the CPA in a factory layer; and communicatively connecting the factory layer to the cloud layer via a networking layer.

Thus, with the applications of the embodiments of the disclosure, the maintenance time can be shortened by using a VR manner or an AR manner, and a cyber physical agent (CPA) can be used to simultaneously monitor and repair plural machines of the same machine type.

It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:

FIG. 1 is a schematic diagram showing a system for machine tool maintenance and repair in accordance with some embodiments of the disclosure;

FIG. 2 is a schematic diagram explaining a SOP-AVR mode and an EG-AVR mode for machine tool maintenance and repair in accordance with some embodiments of the disclosure;

FIG. 3A illustrates a schematic flow chart showing a method for machine tool maintenance and repair in a modeling stage according to some embodiments of the disclosure;

FIG. 3B illustrates a schematic flow chart showing a method for machine tool maintenance and repair in an operating stage according to some embodiments of the disclosure; and

FIG. 3C illustrates a schematic flow chart showing a method for machine tool maintenance and repair in an updating stage according to some embodiments of the disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

Embodiments of the disclosure provide a system and a method for machine tool maintenance and repair, thereby enabling an expert at a remote site to collaborate with an on-site personnel located beside a machine tool to maintain or repair the machine tool by integrating a VR or AR model with the physical machine tool. Embodiments of the disclosure provide two maintenance modes which are an augmented virtual reality model guided by a standard operation procedure (referred as a SOP-AVR mode), and an augmented virtual reality model guided by an expert operation procedure (referred as an EG-AVR mode). In the SOP-AVR mode, if the maintenance causes and items belong to known standard operation procedures, the on-site personnel enters a maintenance instruction mode to perform maintenance or repair, and during the maintenance or repair, the system will instruct the on-site personnel step by step in accordance with a state of the tool machine maintained or repaired by the on-site personnel. If the maintenance causes are beyond the expected or predetermined states of the machine tool, the system will contact the expert (such as a vendor) and send operation states of the machine tool before malfunction to the expert, thereby enabling the expert to well know the operating information for effectively resolving the failure causes, i.e. the EG-AVR mode. After the EG-AVR mode begins, in addition to resolving the failure causes, the new contents of resolving the failure causes will be added to the standard operating procedure via the cloud layer, so as to provide a robust maintenance procedure.

AVR is a collective term of AR and VR. Both of the AR and VR are used for displaying a virtual world, but there are differences between them, in which the AR enables a virtual world and a physical world to be integrated and interactive by calculating the position and angle of an image captured by a camera in addition to an image analysis technology; and the VR generates a virtual world by computer simulation, thereby allowing a user to sense the environment with hearing and vision, such that the user may experience the environment personally and be free to observe the objects in the environment in time. Meanwhile, in the VR, when the user moves to a new position, the virtual scene is changed at the same time, thus providing the user with actual liveness.

Referring to FIG. 1, FIG. 1 is a schematic diagram showing a system for machine tool maintenance and repair in accordance with some embodiments of the disclosure. As shown in FIG. 1, the system includes a cloud layer, a networking layer and a factory layer. A human cyber physical system 100 is a cloud server disposed on the cloud layer. The networking layer includes a gateway 110 and firewalls 112 and 114 for data transmission between the cloud layer and the factory layer. A plant (on-site) and a remote-site are located on the factory layer. An expert device 140 is located at the remote site for allowing an expert 142 to access data. At least one cyber-physical agents (CPA) 120 a, 120 b and/or 120 c are disposed at the plant, in which each of the CPAs is in charge of one or more machine tools. For example, the CPA 120 a is in charge of the machine tools 122 a-122 c; the CPA 120 b is in charge of the machine tools 124 a and 124 b; and the CPA 120 c is in charge of the machine tool 126, in which the machine tools 122 a-122 c have the same machine type, and the machine tools 124 a and 124 b have the same machine type. An on-site device 130 is disposed at the plant for allowing an on-site personal 132 to access data.

Plural sensors are installed on each of the machine tools 122 a/122 b/122 c, 124 a/124 b, and 126 for collecting plural sets of state data of the machine tool that is in operation. In one embodiment, the machine tools 122 a/122 b/122 c are rotary machines, and the sensors includes a dynamometer, an energy consumption sensor and a temperature sensor for detecting abnormalities and preventive maintenance of the machine tools. The dynamometer is used to capture vibration signals of the rotary machine (mechanism), thereby detecting vibration frequencies of the rotary machine that is in operation, and determining the operation state of the rotary machine in accordance with magnitudes and wave forms of the vibration frequencies. The energy consumption sensor is used to collect signals of voltage, current, power consumption, etc. of the machine tool that is in operation, and to diagnose the operating state of the machine tool. The temperature sensor is used to determine the operating state of the machine tool when the rotary mechanism is in operation by detecting a temperature cure change of the machine tool. The CPA 120 a integrates and weighted all the sensing information to evaluate the current states of the machine tool 122 a, 122 b or 122 c.

The human cyber physical system 100 includes a processor and a database. The human cyber physical system has a visual initial-state model 102 a and a standard maintenance procedure 104 a, in which the processor builds plural component models of respective parts of the machine tool is built in accordance with measured dimension data of the parts of the machine tool 122 a/122 b/122 c, 124 a/124 b, or 126, and assembles the component models to form the visual initial-state model in accordance with exploded view data of the machine tool. The processor analyzes periodical maintenance conditions and abnormal states encountered by the machine tool that is in operation, thereby building the standard maintenance procedure. Because the machine tools 122 a, 122 b and 122 c have the same machine type, only one visual initial-state model 102 a and only one standard maintenance procedure 104 a are needed. Because the machine tools 124 a and 124 b have the same machine type, only one visual initial-state model 102 a and only one standard maintenance procedure 104 a are needed. The visual initial-state model 102 a and the standard maintenance procedure 104 a are stored into the database of the human cyber physical system 100.

The CPAs 120 a, 120 b and 120 c are software or firmware circuits, and includes memories. The CPAs 120 a, 120 b and 120 c are communicatively connected to the human cyber physical system 100 for receiving the standard maintenance procedure 104 a. The CPA 120 a is communicatively connected to the machine tools 122 a, 122 b and 122 c for receiving the sets of state data collected by the corresponding sensors. The CPA 120 b is communicatively connected to the machine tools 124 a and 124 b for receiving the sets of state data collected by the corresponding sensors. The CPA 120 c is communicatively connected to the machine tool 126 for receiving the sets of state data collected by the corresponding sensors. The CPA 120 a, 120 b or 120 c or the human cyber physical system 100 updates the visual initial-state model 102 a as a visual operating-state model 102 b in accordance with the sets of state data, and the CPA 120 a, 120 b or 120 c obtains an event standard maintenance procedure 104 b from the standard maintenance procedure 104 a in accordance with the sets of state data. In one embodiment, the visual initial-state model 102 a is first downloaded to the CPA 120 a, 120 b or 120 c, and then is updated as the visual operating-state model 102 b in the CPA 120 a, 120 b or 120 c, and thereafter the visual operating-state model 102 b is sent back to the human cyber physical system 100. In the other embodiment, the visual initial-state model 102 a is directly updated as the visual operating-state model 102 b in the human cyber physical system 100, and then the visual operating-state model 102 b is downloaded to the CPA 120 a, 120 b or 120 c.

The on-site device 130 is communicatively connected to the CPA 120 a, 120 b or 120 c for enabling the on-site personnel 132 to access the visual operating-state model 102 b and the event standard maintenance procedure 104 b. The expert device 140 is communicatively connected to the human cyber physical system 100 for enabling the expert 142 to access the visual operating-state model 102 b, in which the expert 142 enters an expert maintenance procedure 144 into the expert device 140, and then the expert device 140 provides the expert maintenance procedure 144 to the on-site personnel 132 through the human cyber physical system 100. The on-site device 130 and the expert device 140 are VR devices or AR devices.

In one embodiment, the processor of the human cyber physical system 100 can be realized by, for example, one or more processors, such as central processors and/or microprocessors, but are not limited in this regard. In one embodiment, the memory of the human cyber physical system 100 includes one or more memory devices, each of which comprises, or a plurality of which collectively comprise a computer readable storage medium. The memory may include a read-only memory (ROM), a flash memory, a floppy disk, a hard disk, an optical disc, a flash disk, a flash drive, a tape, a database accessible from a network, or any storage medium with the same functionality that can be contemplated by persons of ordinary skill in the art to which this invention pertains. Each of the on-site device 130 and the expert device 140 includes a display device and a controller. The display device can be realized by, for example, a display, such as a liquid crystal display, or an active matrix organic light emitting display (AMOLED), but is not limited in this regard. The controller can be realized by, for example, a handheld controller, such as a controller for Vive or a controller for Gear, but is not limited in this regard.

Hereinafter, the CPA 120 a is used for explaining the SOP-AVR mode and the EG-AVR mode of the disclosure. At first, a 3-D model of the machine tool 126 is built. Before building the 3D model, dimensions of respective parts of the machine tool 126 are measured. Then, component models of the parts of the machine tool 126 are built. Thereafter, the component models are assembled under an AVR software environment in accordance with exploded view data of the machine tool, so as to form the visual initial-state model 102 a. Then, an operation is performed to set up motion states of the components, in which periodical maintenance conditions and abnormal states encountered by the machine tool that is in operation (i.e. when the machine tool is being operated) are analyzed. After the periodical maintenance conditions and abnormal states listed, the standard maintenance procedure 104 a is built in accordance with the strategic analysis and discussion of the expected issues.

When the following items occur during the operation of the machine tool 126, the CPA 120 c will automatically trigger an abnormal event and record the state history (state data) of the machine tool 126. The items include changes of application or operation states (such as various states of “Auto”, “Jog” or “MDI” (Manual Data Input)), user-defined triggers (such as M code), override changes, axial over-travel warnings and controller warnings. The abnormal event includes an over-travel event, an over-heat event or an over-load event. The CPA 120 c or the human cyber physical system 100 updates the visual initial-state model 102 a as the visual operating-state model 102 b in accordance with the sets of state data, and the CPA 120 c obtains the event standard maintenance procedure 104 b from the standard maintenance procedure 104 a in accordance with the sets of state data, in which the event standard maintenance procedure 104 b displays the trigger conditions and the problem solutions that are listed by features under the AVR environment, in which the display is designed to classify the malfunction categories by subjects, thereby allowing the on-site personnel 132 to conveniently inspect and resolve the malfunctions of the machine tool 126 under the AVR environment, After the malfunctions of the machine tool 126 are resolved, the sensors of the machine tool 126 will collected the update state data of the machine tool 126 and the visual operating-state model 102 b will be updated accordingly. The aforementioned description is the explanation of the SOP-AVR mode.

Hereinafter, the EG-AVR mode is explained. The EG-AVR mode is activated by a trigger instruction under the SOP-AVR mode. When the malfunction of the machine tool 126 is beyond that listed or expected in the SOP-AVR mode, the on-site personnel 132 may select to activate the EG-AVR mode. The EG-AVR mode brings two or more expert 142 and the on-site personnel 132 at different sites (the on-site and the remote-site) to one identical virtual display, thereby allowing them to discuss with respect to the same machine tool in the same display, in which sound and captions may added to the display, such as shown in FIG. 2. For example, the expert 142 may speak through a microphone of the expert device 140 to say “Hello, this is a development engineer of this machine tool.”, and meanwhile, the on-site personnel 132 in the same VR environment may hear the voice of the expert 142 through a speaker of the on-site device 130, and a dialog window may appear besides a virtual character representing the expert 142, thereby displaying the captions. After the expert device 140 provides the expert maintenance procedure 144 to the on-site personnel 132 to resolve the malfunctions or emergencies that are not expected by the SOP-AVR mod, the expert maintenance procedure 144 is used to update synchronously the standard maintenance procedure 104 a corresponding to the machine tools having the same machine type with the machine tool 126.

A method for machine tool maintenance and repair according to embodiments of the disclosure is explained hereinafter, in which the method is divided into a modeling stage, an operating stage and an updating stage.

Referring to FIG. 3A, FIG. 3A illustrates a schematic flow chart showing a method for machine tool maintenance and repair in the modeling stage according to some embodiments of the disclosure. In the modeling stage, operation 310 is performed to install plural sensors on each of at least one machine tool for collecting plural sets of state data of the machine tool that is in operation. Operation 312 is performed to build a visual initial-state model (state model) in accordance with a physical machine tool structure (measured dimension data of parts of the machine tool), assembling procedures (exploded view data of the machine tool), positions of the sensors and operating states. Operation 314 is performed to analyze possible events of periodical maintenance conditions and abnormal states encountered by the machine tool that is in operation, so as to build SOP-VAR maintenance procedures for the respective events and then build a standard maintenance procedure, in which the SOP-VAR maintenance procedures includes sub-procedures of checking, disassembling and inspecting. Operation 316 is performed to store the visual initial-state model and the standard maintenance procedure in a human cyber physical system.

Referring to FIG. 3B, FIG. 3B illustrates a schematic flow chart showing a method for machine tool maintenance and repair in the operating stage according to some embodiments of the disclosure. In the operating stage, operation 320 is performed to communicatively connect a CPA to the at least one machine tool and the human cyber physical system for receiving the standard maintenance procedure and the sets of state data collected by the sensors of the machine tool that is in operation. Through the sensors of the machine tool, the CPA may automatically record the operating history of the machine tool and synchronously updates the visual initial-state model as a visual operating-state model. When the machine tool is abnormal, operation 322 is performed to communicatively connect an on-site device to the CPA for enabling an on-site personnel to access the visual operating-state model and to obtain an event standard maintenance procedure from the standard maintenance procedure. Meanwhile, the on-site personnel first handles the abnormal machine tool in accordance with a SOP-AVR maintenance procedure (the standard maintenance procedure) suggested by the CPA. If the SOP-AVR maintenance procedure fails to resolve the problems of the machine tool, operation 324 is performed to communicatively connect an expert device to the human cyber physical system for enabling an expert to access the visual operating-state model. After the communication between the CPA and the human cyber physical system is built, the on-site personnel and the expert at the remote-site may be collaborated together to perform maintenance and repair on the machine tool. Thereafter, operation 326 is performed, in which the expert enters an expert maintenance procedure into the expert device, and then the expert device uploads the expert maintenance procedure to the human cyber physical system, thereby enabling the on-site personnel to access the expert maintenance procedure through the on-site device. In operation 326, the expert may simulate the maintenance procedures under various conditions by using the visual operating-state model, for example, changing the order of different axial motors, so as to inspect the causes of abnormality of the machine tool. Then, the human cyber physical system will instruct the on-site personnel with the simulated maintenance steps of the machine tool (the expert maintenance procedure) step by step.

If the result of maintenance and repair does not meet the expectation of the expert maintenance procedure, then the expert is asked to provide another suggestion. If the result of maintenance and repair meets the expectation of the expert maintenance procedure, the method enters the updating stage to update the standard maintenance procedure synchronously by using the expert maintenance procedure, such as shown in operation 330 of FIG. 3C.

It can be known from the aforementioned embodiments that, the maintenance time is shortened by using a VR manner or an AR manner, and a cyber physical agent (CPA) is used to simultaneously monitor and repair plural machines of the same machine type.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosure without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this invention provided they fall within the scope of the following claims. 

What is claimed is:
 1. A system for machine tool maintenance and repair, the system comprising: at least one machine tool, wherein a plurality of sensors are installed on each of the at least one machine tool for collecting a plurality of sets of state data of the machine tool that is in operation, and the at least one machine tool has the same tool type; a human cyber physical system having a visual initial-state model and a standard maintenance procedure, wherein a plurality of component models of respective parts of the machine tool are built in accordance with measured dimension data of the parts of the machine tool, and the component models are assembled to form the visual initial-state model in accordance with exploded view data of the machine tool; and the human cyber physical system analyzes periodical maintenance conditions and abnormal states encountered by the machine tool that is in operation, thereby building the standard maintenance procedure; a cyber-physical agent (CPA) communicatively connected to the at least one machine tool and the human cyber physical system for receiving the standard maintenance procedure and the sets of state data, wherein the CPA or the human cyber physical system updates the visual initial-state model as a visual operating-state model in accordance with the sets of state data, and the CPA obtains an event standard maintenance procedure from the standard maintenance procedure in accordance with the sets of state data; and an on-site device communicatively connected to the CPA for enabling an on-site personnel to access the visual operating-state model and the event standard maintenance procedure.
 2. The system of claim 1, further comprising: an expert device communicatively connected to the human cyber physical system for enabling an expert to access the visual operating-state model, wherein the expert device provides an expert maintenance procedure to the on-site personnel.
 3. The system of claim 1, wherein the visual initial-state model and the visual operating-state model are virtual reality (VR) models or augmented reality (AR) models, and the on-site device and the expert device are VR devices or AR devices.
 4. The system of claim 1, wherein the at least one machine tool is a rotary machine, and the sensors comprises a dynamometer, an energy consumption sensor and a temperature sensor.
 5. The system of claim 1, further comprising: a cloud layer comprising the human cyber physical system; a factory layer comprising the at least one machine tool and the CPA; and a networking layer communicatively connecting the factory layer to the cloud layer.
 6. A method for machine tool maintenance and repair, the method comprising: installing a plurality of sensors on each of at least one machine tool for collecting a plurality of sets of state data of the machine tool that is in operation; building a plurality of component models of respective parts of the machine tool in accordance with measured dimension data of the parts of the machine tool, and assembling the component models are assembled to form a visual initial-state model in accordance with exploded view data of the machine tool; analyzing periodical maintenance conditions and abnormal states encountered by the machine tool that is in operation, thereby building a standard maintenance procedure; storing the visual initial-state model and the standard maintenance procedure in a human cyber physical system; communicatively connecting a cyber-physical agent (CPA) to the at least one machine tool and the human cyber physical system for receiving the standard maintenance procedure and the sets of state data; updating the visual initial-state model as a visual operating-state model in accordance with the sets of state data, and obtaining an event standard maintenance procedure from the standard maintenance procedure in accordance with the sets of state data; and communicatively connecting an on-site device to the CPA for enabling an on-site personnel to access the visual operating-state model and the event standard maintenance procedure.
 7. The method of claim 6, further comprising: communicatively connecting an expert device to the human cyber physical system for enabling an expert to access the visual operating-state model; entering, by the expert, an expert maintenance procedure into the expert device; and uploading, by the expert device, the expert maintenance procedure to the human cyber physical system, thereby enabling the on-site personnel to access the expert maintenance procedure through the on-site device.
 8. The method of claim 7, wherein the visual initial-state model and the visual operating-state model are VR models or AR models, and the on-site device and the expert device are VR devices or AR devices.
 9. The method of claim 6, further comprising: disposing the human cyber physical system in a cloud layer; disposing the at least one machine tool and the CPA in a factory layer; and communicatively connecting the factory layer to the cloud layer via a networking layer.
 10. The method of claim 6, wherein the at least one machine tool is a rotary machine, and the sensors comprises a dynamometer, an energy consumption sensor and a temperature sensor. 